Anisotropic magnetic damping and interface spin transport in fully epitaxial cubic Fe74V26/Pt heterostructure

The directional control of magnetic damping and interfacial spin transport has emerged as a promising yet challenging route toward anisotropic spintronic devices. In this work, we investigated the magnetic damping and spin-pumping effect of fully epitaxial Fe74V26/Pt heterostructures by ferromagnetic resonance measurements along the easy and hard magnetization axes. Both the intrinsic damping αint of the Fe74V26 film and the effective spin mixing conductance Geff↑↓ of the heterostructure exhibit a pronounced anisotropy. The anisotropic αint may be associated with crystallographic-direction-dependent spin–orbit coupling based on magnetoresistance measurements. The directional dependence of Geff↑↓ indicates that the interfacial spin transport is inherently anisotropic. First-principles calculations trace this interfacial anisotropy predominantly to the Pt layer, where a pronounced directional character in the interfacial density of states is found. This anisotropy can influence the spin-dependent scattering at the interface, providing a consistent microscopic picture for the directional spin transport observed experimentally. These findings offer new insights into the interplay between interfacial electronic structure and spin transport in epitaxial magnetic heterostructures.